Microelectromechanical structures (MEMS) are very small mechanical structures, usually formed using semiconductor processing processes. Such structures may be formed as resonators, and used as sensors, and vibrate in response to a sensed parameter or applied force. The displacement of such vibrations are generally very small, since the MEMS structure itself is generally very small, in the range of micrometer to nanometers. There is a need for a MEMS structure that provides a larger displacement in response to small forces.
Presently, there is a need in micro-electromechanical technology for a resonator that is capable of large motions at low drive voltages. Large, linear displacements are obtained by using comb drive actuation, however the force of a comb drive is low and large drive voltages, and numbers of comb teeth are needed. Parallel-plate drive actuation generates larger forces over a comparable area, however the displacement is limited because the force is nonlinear. Magnetic actuation produces large forces, but is limited to low frequency, and requires heavy electroplated ferromagnetic materials. Lorentz coil actuation similarly faces inductance limits and requires substantial currents and hence high power levels.